This article explains how to handle issue when Web Application load is not working properly.
Error occurred while loading Web Application
While trying to load a SharePoint farm the following error message was displayed:
Error occurred while loading ‘Application Name’ Web Application
and the following error messages are stored in the event log:
The following sites are not loaded properly because you do not have the right privileges for these databases. Unavailable databases:
The user running the application needs to have proper privileges to access the information about Site Collections stored in the content databases. See this article for more details on configuring privileges.
If you are still having issues with individual Web Applications or other items you need to do the following: make sure the user has Shell access to the given content database, using the following PowerShell code to grant access:
$spcdb = Get-SPContentDatabase WSS_Content_Intranet Add-SPShellAdmin -UserName DOMAIN\User -Database $spcdb